Robust fabrication of nanomaterial-based all-solid-state ion-selective electrodes

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Nanomaterial-based all-solid-state ion-selective electrodes (ASS-ISEs) are valuable for environmental and biological sensing.
• Poor adhesion of nanomaterial solid contacts limits the widespread use of ASS-ISEs.

Purpose of the Study:

• To develop a general and facile method for robust fabrication of nanomaterial-based ASS-ISEs.
• To improve the adhesion and stability of nanomaterial solid contacts in ASS-ISEs.

Main Methods:

• Fabrication of nanomaterial-based solid contacts using a silver-based conductive adhesive (CA) as a binder.
• Utilizing a solid-contact Calcium ion-selective electrode (Ca2+-ISE) based on single-walled carbon nanotubes (SWCNTs) as a model system.
• Characterization of electrochemical properties including response linearity, detection limit, potential stability, and water film formation.

Main Results:

• The CA-SWCNT-based Ca2+-ISE demonstrated a linear response from 10^-6 to 10^-3 M with a slope of 25.96 ± 0.36 mV/decade and a detection limit of 1.7 × 10^-7 M.
• The electrode exhibited improved potential stability and reduced water film compared to coated-wire ISEs.
• Electrochemical characteristics (resistance, capacitance, potential stability) of the CA-SWCNT electrode were comparable to traditional SWCNT-based electrodes.

Conclusions:

• Conductive adhesive (CA)-nanomaterial-based solid contacts offer a robust and effective alternative to traditional solid contacts.
• This method enhances the practicality and reliability of nanomaterial-based ASS-ISEs for various sensing applications.